Surface analysis of biocompatible coatings on titanium

The coatings of hydroxyapatite, which is widely used for orthopaedic and dental prothesis, were deposited by using the dip-coating method. The layers of hydroxyapatite were grown on commercial Ti substrates. In order to improve the adhesion of hydroxyapatite, the substrate was a priori covered with titania or calcium titanate by using the sol-gel technique. For comparison, commercial samples of hydroxyapatite coating (manufactured by means of plasma-spray apparatus) were analysed. The chemical composition and the structure of the coatings (TiO2, CaTiO3 and hydroxyapatite) were studied by using X-ray photoelectron spectroscopy (XPS), scanning Auger microscopy (SAM), X-ray diffraction (XRD) and secondary electron microscopy (SEM) techniques. The data of quantitative XPS analysis and the surface images (SAM and SEM) displayed the superior quality (cleanness, homogeneity, etc.) of hydroxyapatite deposited by sol-gel in comparison with commercial samples investigated.